package 链表.easy;

import 链表.middle.YiSiEr;

/**
 * @author Lw中
 * @date 2020/9/27 9:53
 */
public class ErYi {

    class ListNode {
        int val;
        ListNode next;
        ListNode() {}
        ListNode(int val) { this.val = val; }
        ListNode(int val, ListNode next) { this.val = val; this.next = next; }
    }

    /**
     * 合并两个有序链表
     * 使用递归方法
     * @param l1
     * @param l2
     * @return
     */
    public ListNode mergeTwoLists(ListNode l1, ListNode l2) {
        if (l1 == null) {
            return l2;
        }
        if (l2 == null) {
            return l1;
        }
        /**
         * 递归片段不清楚
         * LWZ TODO : 2020/9/27
         *
         */
        if (l1.val < l2.val) {
            l1.next = mergeTwoLists(l1.next, l2);
            return l1;
        } else {
            l2.next = mergeTwoLists(l1, l2.next);
            return l2;
        }
    }

    public static void main(String[] args) {

    }

}
